1. Field of the Invention
This invention generally relates to beverage brewers, and more particularly, beverage brewers that permit selectively changing batch quantities for different brew cycles.
2. Discussion of the Prior Art
Both the time of contact of the not water with the beverage ingredient and the amount of hot water that is mixed with a given amount of beverage are critical to optimizing the quality of the resulting brewed beverage. Different types of beverage ingredient, such as different types of coffee, and different forms of a given beverage ingredient, such a given ground coffee of different degrees of coarseness required different amounts of hot water for optimum brewing of the resulting beverage. However, until recently, known coffee brewers were unable to easily adjust the quantity of hot water that is dispensed without changing the duration of the dispensing time period. Likewise, it was difficult to easily adjust the duration of the dispense period without changing the quantity of hot water that is to be dispensed.
However, with my invention shown and claimed in U.S. Pat. No. 6,148,717 issued Nov. 21, 2000 to Zbigniew G. Lassota for xe2x80x9cBeverage Maker With Intermittent Beverage Liquid Dispenser and Apparatus and Method for Uniform Contact or Brew Ingredient with Brewxe2x80x9d, which is hereby incorporated by reference, apparatus and methods were shown that enabled easy selectively control of the average rate at which hot water is dispensed into a brew basket of a brewer so as to selectively change the quantity of hot water that is dispensed independently of the duration of the dispense period to optimize brew abstraction from the dry beverage ingredient such as ground coffee during the brew cycle by intermittently operating a single dispense valve. With the invention of that patent is also possible to selectively change the length of the dispense time period without changing the batch quantity, again for purposes of optimizing abstraction, by intermittently operating a single valve.
While intermittent operation works successfully for the intended purposes of fine-tuning control over the dispense period of the brew cycle, repeated operation of the dispense valve is required for each dispense period with attendant mechanical wear and fatigue.
Other brewers are known in which the dispense valve is operated continuously and in which the batch quantity may be changed, but the change in quantity requires a change in the dispense time period and vice versa, and thus the desired degree of control of quantity and dispense period duration is not achievable.
It is also known to use a variable speed pump vary delivery rate on a continuous basis rather than intermittently to enable independent control of quantity and dispense time duration. Use of a pump believed to be subject to high maintenance costs due to the mechanical movement and liming. It is also known to use a flexible tube that are selectively restricted to change the rate of flow into a brew basket but adjustment is achieved only through manual adjustment of a control knob and the use of plastic tubing may be unsuitable for use with food and hot water.
It is therefore an object of the present invention to provide a brewer and method of brewing that enable independent control of the batch quantities and the duration of the dispense time period during which hot water is dispensed into the brew basket without the need for intermittent operation of a dispense valve or the disadvantages of a variable speed pump or flexible tube.
In accordance with one aspect of the invention this control is achieved by provision of multiple dispense valves that are independently controllable. In one embodiment, more or fewer of the dispense valves are selectively actuated simultaneously during a single dispense time period to respectively increase or decrease the dispense flow rate during the dispense period.
In another embodiment, the dispense valves are of different size, and different rates are achieved during different dispense periods by selectively actuating only one of the valves during the single dispense time period. Actuation of a larger valve results in a greater flow rate and a larger batch size for a dispense period of given duration than actuation of a relatively smaller dispense valve for the same duration.
In yet another embodiment with a brewer of the type in which a fixed quantity of hot dispense water is xe2x80x9cdumpedxe2x80x9d, i.e., is dispensed from the hot water tank by draining the tank to a preselected level without the tank being refilled until after the end of the dispense period, the plurality of dispense valves have inlets connected to the hot water tank at the plurality of different preselected levels and different sizes indirectly related to the level at which they are located to enable each dispense valve to xe2x80x9cdumpxe2x80x9d the quantity of dispense water associated with the inlet level during dispense time periods of equal duration.